If Tony had not started the project so early, he would never have finished on time.
簡化-->Had Tony not started the project so early, he would never have finished on time.
如果(當時)Tony沒有提早開始專案,他(當時)就不會在時間內完成。-->與過去事實相反的假設語氣
如果湯尼沒有那麼早開始進行這項工作,他就不可能準時完成。
Had+主詞+(not) started=If+主詞+had (not) started. 與過去事實相反的假設語氣
39. ___________ the project so early, he..-阿摩線上測驗